What matters are the commitments Larian has made to retailers and such, commitments that they cannot break. The only flexibility Larian has in adjusting the release date comes from what the retailers (et al) will grant them, regardless of how many people on the forums are okay with Larian needing to take more time.
What retailers are you talking about? I haven't seen D:OS being available for pre-orders anywhere yet, even on Steam. And even if there were, believe me, retailers are quite flexible with release dates - I've seen them change countless times on Amazon.
The only commitment I'm aware of is delivering the game to Kickstarter backers in a promised state within a reasonable amount of time.
